Some present day fluorescent lighting fixtures use a type “2D” lamp as the source of illumination.
Thorn EMI Lighting in the United Kingdom conceived the “2D” fluorescent lamp in 1981. The lamp was so named because it resembles a pair of the letters “D” placed back to back. General Electric Lighting, who introduced several different sizes and wattages to the “2D” style product line, is now manufacturing the lamps. The line was expanded to include five different wattage ratings, ranging from 10 to 38 watts and having three different base styles.
Two of the smaller lamps in the series have starters included in the base of the lamp, hence requiring only two pins for an interconnection. The remaining three lamps in the series, each being of the larger wattage, do not use starters. It therefore becomes necessary to use four pins to interconnect with its respective ballast.
This style of lamp has an average rated life of between 8,000 to 10,000 hours dependent upon its wattage rating and size. A type “2D” lamp is more costly than the time proven and tested twin circular fluorescent lamp, which normally has an average rated life of ranging between 9,000 and 12,000, costing about one-half as much and having a greater lumen output.
To obviate the need for replacing the type “2D” fluorescent lamp with an identical less reliable replacement lamp, the present invention allows the substitution using a replacement lamp that is more commonly available, and one that demonstrates a long life of operation.
The following prior art discloses the various aspects in the design and use of the “2D” series fluorescent lamp and its application.
U.S. Pat. No. 6,083,021, granted Jul. 4, 2000, to K. Lau, discloses a lamp assembly mount that is adapted to receive a specific commercially available fluorescent lamp that is known as the “2D” lamp. This lamp is commercially produced in several different sizes, having several different wattage ratings. Because the design of the base of the “2D” lamp is specific to its wattage rating, the lamp assembly mount will only receive the correct lamp, thereby eliminating the interchangement with higher or lower wattage fluorescent lamps.
U.S. Pat. No. 5,471,375, granted Jul. 4, 2000, to K. Lau, discloses a lamp mounting base assembly that is adapted to mount a specific commercially available fluorescent lamp. The unit is characterized by the design of a ballast housing to fit inside a space defined by the fluorescent lamp internally of the surrounding, somewhat annular fluorescent tube. The base assembly is designed to minimize the mounting of under- or over-wattage fluorescent tubes.
Presently, the prior art teaches of a fluorescent lamp base assembly that is uniquely configured for application using a specific wattage “2D” type of fluorescent lamp source of illumination to prevent the interchangement with other types of fluorescent lamps and more specifically with other “2D” fluorescent lamps having different wattage ratings.
Hence, the prior art recited above does not teach of the novel advantages that are found in the present invention.
What is needed is a universal adaptor, one that is universal in design, and one that allows the use of a more reliable twin circular fluorescent lamp, a lamp having greater illumination intensity, thereby permitting the substitution of the less reliable, less efficient, type “2D” fluorescent lamp.
Safety being of primary concern, the novel adaptor is interlocking and sealed as a means of being tamperproof to eliminate the potential of receiving an electrical shock.
In addition, lamp wattages greater than the UL approved design wattage rating cannot be used, thereby preventing it to contributing in being a fire hazard. In this regard, the present invention fulfills this need.